Process of platinumizing metal surfaces.



numizing compound I in connection with metals which are diflicult to plate by the ordinary electrical deposi-- T STA BENJAMIN B. GROMBIE, OF PORT CHESTER, YORK.

PROCESS OF PLATINUMIZING METAL SURFACES.

No Drawing.

To all whom it may concern:

Be it known that I, BENJAMIN B. CRoM- BIE, a citizen of the Dominion of Canada, residing at Port Chester, in the county of Westchester and State of New York, have invented new and useful Im rovements in Processes of Platinumizing etal Surfaces, of which the following is a specification.

his invention relates to improvements in means and processes used in depositing a permanent coating of platinum upon the surface of another metal.

he principal object of this invention is to provide a process for plating metals with platinum by the use of chemical and mechanical means only.

A further object is to provide a platinumizing means applicable broadly to any metal, which is easily and quickly applied .and of the utmost durability, the coating becoming a component part of the metal surface covered by it, indivisible and inseparable, irrespectlve of its thickness, which depenls upon the quantity of composition use A still further object is to provide a platicapable of being used tion of metals, as alummum, and further, can be applied within the interior of cylindrical and concave metallic articles, that are impossible to plate by usual electrical processes.

These objects are attained by the novel means, processes and principles hereinafter fully described, explalned and set forth in the accompanyin claims.

. The surface 0 the metallic article to be coated. should be clear of oxidization, scale, grease or the like, in fact, both mechanically and chemically clean.

he plating composition consists of a normal platinum chlorid solution (PtCl,,) ten parts and a normal ammonium chlorid solution (NH,CI) eighteen parts forming ammonio platino chlorid, (NH (2PtCl,) which is precipitated as a yellow powder.

To one part by weight of the ammonio platinio chlorid, add eight parts by wei ht, of potassium bi-tartrate .(KHQH, and three parts by weight of'distilled water.

his composition is applied to the polished surface of the metal article to be Specification of Letters Patent. Application filed March 29, 1918. Serial No. 225,461.

Patented Aug. 6, was.

plated by a chamois leather dipped in the paste and rubbed vigorously upon the metal surface, the operation being continued or repeated until a desired thickness has been secured.

Obviously the interiors of cylindrical or concave articles in which it is possible to apply the ammonio platino chlorid paste can be effectually covered, as well as the exteriors, as theoperation of application is purely mechanical, while adhesion and durability are attained by the chemical afiinitative action of the paste upon the metal to which it is applied.

The foregoing process renders it possible to coat or plate articles made of base metal, which after being treated, possess substantially all the advantages, appearances and characteristics, of solid platinum, as for instance articles of jewelry, dental goods and laboratory appliances, etc.

it is desired to produce a highly polished surface, the metallic article, with its first coating of platinum, is placed in a mixture of twelve parts of platinum chlorid, four parts ammonio platino chlorid, and eighty-four parts water, pure platinum foil being used as an anode and the article to be coated as the cathode, and a mild electrical current passed through the solution.

Having thus described my invention and set forth as new and desire cut, is

1. The herein described process of depositing platinum upon metallic surfaces, consisting of the mechanical application of a paste comprised of ammonio platino chlorid one part, potassium bi-tartrate eight parts and .distilledwater three parts, all substantially as set forth.-

2. The herein described process of platinumizing metals, consisting of first mechanically and chemically cleansing the metal to be plated, and applying a paste comprised of ammonio platino chlorid one part, potassium bi-tartrate eight parts, and distilled water three arts, by means of a friction pad and contlnuing until a desired depth of deposition has been attained,

3. The herein described process of platinumizing metallic surfaces consisting of cleansing the surface to be plated, rubbing the surface with a paste comprised of amto secure by Letters Patthe manner of its use, what I claim monio platino chlorid one part, potassium bi-tart1rate eight parts, and distilled Water tlmree parts, until the surface is coated andl then subjecting the plated article as a 5 cethodle in a IlllXtllIB of twelve parts platinum chloriel, four parts ammonio platino chloridl, and eighty-four parts water, using ev/wee an anode of pure platinum foil and passing electric current from the anocle to the cathode. 10

In testimony whereof, l have signed myname to this specification.

BENJAMIN B. meet/min. 

